Sergeant Bob Smith, of BTP, said: “The behaviour of Johnson and the group he was with was absolutely disgraceful and must have been extremely frightening for other fans, passengers and staff on the train and at the station.

“The group, who were high on drugs and drink, were intent on a fight and after initially targeting other passengers they then turned on officers.

“Luckily the officer didn’t sustain any serious injuries but the force used by Johnson to stamp on his back whilst he was trying to restrain and arrest a violent man could have quite easily caused serious and permanent damage to his back and spine.”